Best Doom-clone on vanilla A500?

[Rebel-CD32]

Originally Posted by eXeler0

Somehow they did this on the Mega Drive with 64k video ram

[ Show youtube player ]

I suppose its a given that a vanilla 500 (or maybe a 500+ and 600 1MB version) would need to rely on ALL the tricks and hacks you can possibly shake out of the 68000, the Copper and the Blitter.

But therein lies the challenge and the fun, doesnt it? ;-)

Doom is running on the 32X hardware, it won't run on the Mega Drive.

Wolfenstein, however, runs beautifully on a standard Mega Drive. It's running in 16 colours, like the Atari ST and Apple IIGS versions, but is using the PC version's 256 colour graphics and dithering them in real-time using a lookup table for dither patterns.

[ Show youtube player ]

[eXeler0]

Looks pretty good. Was that ever an official release or is it homebrew stuff?

[ReadOnlyCat]

Originally Posted by Samurai_Crow

Stock or acclerated? It's really hard to milk a stock A500 and still use texture mapping, especially with minimal RAM.

The target for my personal projects is the stock A500 with 1MB chip RAM but you are right that texture mapping seems too high a goal unless when done with copper chunky. But just to be clear: Doom like stuff is not in my plans, I just like to think about it.

Originally Posted by eXeler0

Somehow they did this on the Mega Drive with 64k video ram [ Show youtube player ]
I suppose its a given that a vanilla 500 (or maybe a 500+ and 600 1MB version) would need to rely on ALL the tricks and hacks you can possibly shake out of the 68000, the Copper and the Blitter.

Oh, interesting. But they use a trick not accessible to the Amiga. (Cf below.)

Originally Posted by vulture

@exeler0

I'm not the biggest expert around here, but I see no reason why miggy couldn't match this on the right hands.

There are plenty of reasons actually:
- the MegaDrive uses its 80 hardware sprites to display all animated objects so they are essentially free
- the game seems to make very smart use of tiled graphics: if you look carefully you will notice jaggies (especially on surfaces almost perpendicular to the line of sight) which would not be there if they used proper per pixel texture mapping. This means that they probably have pre rendered tiles containing the various angles and depths of the walls and just choose the most suited tile for each group of 8x8 pixels. This makes updating the screen much faster than a bitmap of the equivalent size.
- the MD is not slowed down by display DMA so the CPU roams free while the whole display is rendered by the VDP, on the Amiga the CPU can only access memory during the cycles not taken by display, copper and blitter. They might be using that free time to generate some of the tiles displayed.
- the MD has chunky-ish pixel definitions so it probably is simpler to do live texture mapping than on planar architecture like the miggy, I am not excluding the possibility that planar texture mapping might be made efficient but for now I certainly have no idea how to do it.

Originally Posted by hooverphonique

something like that could be possible, i guess, presuming you prescaled the height of all wall textures for all lighting levels.

Which would probably take enormous amounts of memory, which is why I think they probably render some of the tiles on the fly from a pre-calculated set of reference depths and angles.

The rendering window is quite small though so maybe something similar can be reached but I'll stay safely skeptical for now.

[desiv]

Originally Posted by ReadOnlyCat

- the game seems to make very smart use of tiled graphics:

I'll have to see if I can find it again, but wasn't there a Genesis/MD FPS that basically rendered only the top half of the screen (or something), and then flipped the rest for the bottom half (and added some sprites to cover it)?
I could have sworn I read something about that in a discussion of FPS games on slower systems...
I suppose you could get even crazier and render only a strip and tile it??
Limits your wall/door design quite a bit tho...

desiv

[vulture]

@ReadOnlyCat

Yup, I know MD has an edge on that area, I was just basing my assumption on Ambermoon. Almost double the height and half the width of what MD does in Zero Tolerance, but with texture mapped floor and ceiling - MD hasn't got that. So, I thought, why not? And even better, since Ambermoon's engine looks better, it could be the actual basis of a wolfenstein-type game by itself.

EDIT:

from real ST (STFM and STE) hardware with some extra RAM, no other expansion:
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[Rebel-CD32]

This is why Doom works on the Mega Drive/32X combination:

"The 32X contains two Hitachi SH2 32-bit RISC processors with a clock speed of 23 MHz, which Sega claimed would allow the system to work 40 times faster than a stand-alone Genesis. Its graphics processing unit is capable of producing 32,768 colors and rendering 50,000 polygons per second, which provides a noticeable improvement over the polygon rendering of the Genesis. The 32X also includes 256 Kilobytes of random-access memory (RAM), along with 256 Kilobytes of Video RAM."

It's not using any of the Mega Drive's graphic modes so why guess? It's running on completely different hardware and simply pumped out through the Mega Drive's AV holes.

If you really want to know how to write efficient 3D for the Mega Drive you need to talk to GASEGA68k, who programmed the homebrew Wolfenstein port and claims he has an unreleased engine which runs even smoother in a larger window size! He's also coded Starfox and Mario Kart routines for the Mega Drive, two game types which the A500 is also sorely lacking in.

[ReadOnlyCat]

Originally Posted by Rebel-CD32

This is why Doom works on the Mega Drive/32X combination: [...]

It's not using any of the Mega Drive's graphic modes so why guess? It's running on completely different hardware and simply pumped out through the Mega Drive's AV holes.

Why guess? Because we are talking about "Zero Tolerance" on the MegaDrive and not about Doom/32X.

If you really want to know how to write efficient 3D for the Mega Drive you need to talk to GASEGA68k, who programmed the homebrew Wolfenstein port and claims he has an unreleased engine which runs even smoother in a larger window size! He's also coded Starfox and Mario Kart routines for the Mega Drive, two game types which the A500 is also sorely lacking in.

Indeed, lacking they are, and you made me quite curious about these routines but I'll refrain from pursuing the topic because we're fully in off topic land at the moment.

[Rebel-CD32]

Originally Posted by ReadOnlyCat

Why guess? Because we are talking about "Zero Tolerance" on the MegaDrive and not about Doom/32X.



Indeed, lacking they are, and you made me quite curious about these routines but I'll refrain from pursuing the topic because we're fully in off topic land at the moment.

D'oh, I guess when I clicked on the link I missed the first vid somehow and it auto-played a video of Doom on the 32X where the title and comments were trying to imply it was running only on Mega Drive hardware. My mistake, sorry!

[Mrs Beanbag]

i have been pondering lately, the idea of using techniques used in demos, such as sine-wave scrollers, to do texture mapping, with low-resolution textures (maybe 16x16 blocks for the walls).

[waldiamiga]

"Wilczy Szaniec" should work on the A500 . It should because there is only a demo.
[ Show youtube player ]

[vulture]

Nice engine! Crappy gfx, but nice engine if it runs like that on a real A500!

[s2325]

Recording is from 2011, I don't remember WinUAE configuration, sorry.

[eXeler0]

Originally Posted by waldiamiga

"Wilczy Szaniec" should work on the A500 . It should because there is only a demo.
[ Show youtube player ]

Nice.. it looks like something I'd imagine should be possible to pull off on an A500 ;-)
But is there an actual file still in existence in the wild (or locked in somewhere) so that it could be tested on real hardware?

[ReadOnlyCat]

Originally Posted by Mrs Beanbag

i have been pondering lately, the idea of using techniques used in demos, such as sine-wave scrollers, to do texture mapping, with low-resolution textures (maybe 16x16 blocks for the walls).

Please post about the sine wave scroller techniques in the thread I created about Doom like rendering.
They might help rebound the reflection and I'm afraid this thread will explode if we continue to dive deeper in off topic territory.

[s2325]

ADF is on EAB server /Commodore_Amiga/Game/Disk/Wilczy Szaniec (demo-playable)(1996)(Black Friday Production).zip

[vulture]

Well I've tried Wilczy on E-UAE without JIT on my Peg2 (which, imo, is very good indication of how it'd run on an actual A500, since it can barely keep up with the more complex ECS games) and it runs like in the youtube video. So, I think, that's how good it'd run on real hardware as well, which is great!

[s2325]

"Wilczy Szaniec" is translated "Wolfenstein".

[Gzegzolka]

Citadel was fun game, sure You need to resize screen size to gain some speed but game is well balanced.

[waldiamiga]

Originally Posted by s2325

ADF is on EAB server /Commodore_Amiga/Game/Disk/Wilczy Szaniec (demo-playable)(1996)(Black Friday Production).zip

Soon to reveal the source code and the last demo created by author.

[Rebel-CD32]

I just played Wilczy Szaniec on my A500 and can confirm it really does run as smoothly as it does in the video. Surprised the hell out of me! Definitely the smoothest 3D FPS engine I've ever seen on the A500.